In the past, different types of structures for providing a thermal and/or hermetic seal between a door and a surrounding structure have been suggested. One type of sealing structure, disclosed in U.S. Pat. No. 4,807,397, provides a honeycomb sealing structure along each of the hinge and closure sides of the door. The honeycomb structure comprises a base which is connected to the jamb of a door frame and a honeycomb which is integrally connected with the base. The honeycomb structure is formed as a co-extrusion of two different types of thermoplastic elastomer. A semi-rigid thermoplastic elastomer material forms a base which is connected to the jamb of a door frame. A flexible thermoplastic elastomer material forms a honeycomb which is integrally connected with the base. The honeycomb sealing structure extends about the perimeter of the door frame. The honeycomb sealing structure forms a compression seal against the peripheral edges of the door as the door is pivoted to a closed position relative to the door frame.
Another known structure for providing a thermal and/or hermetic seal between a door and a door frame is a magnetic sealing gasket. A base formed of a semi-rigid thermoplastic elastomer material is secured to the jamb of a door frame. A magnetic material is encased in a jacket formed of a flexible thermoplastic elastomer material, and a flexible bellows-like structure, also formed of the flexible thermoplastic elastomer material, connects the jacket to the base. The bellows-like structure biases the magnetic sealing gasket to a predetermined orientation when the door is in an open condition. As the door closes, the magnetic sealing gasket engages a selected part of the door and the flexible bellows-like structure allows a predetermined amount of reachout of the magnetic sealing gasket, to provide an effective thermal and/or hermetic seal between the door and the door frame.
With either a magnetic or a honeycomb type seal, it is important that the sealing structure be biased to an orientation relative to the door frame such that as the door is closed the sealing structure engages the door in a predetermined manner, to provide an effective thermal and/or hermetic seal. Otherwise, the sealing structure may provide an inadequate seal with the door, or might interfere with proper closure of the door.
Also, warpage of the door can make it difficult for a seal structure to achieve an adequate hermetic and/or thermal seal. Specifically, warpage of the door can cause peripheral edge portions of the door (which would normally engage the magnetic and/or honeycomb seal) to bow in such a manner as to make it difficult to achieve an effective thermal and/or hermetic seal about the entire perimeter of the door. In the past, one way the warpage problem has been addressed has been to provide an extrudate which forms a primary seal, and an additional sealing member which is stapled to the extrudate to form a secondary seal. The secondary seal is located to seal selected parts of the door and the door frame, to account for the warpage problem.